Manufacture of lead peroxid and its application to electrical storage batteries.



UNITED STATES PATENT OFFICE.

HERMANN BECKMANN, OF WITTEN, GERMANY.

MANUFACTURE OF LEAD PEROXID AND ITS APPLICATION TO ELECTRICAL STORAGEBATTERIES.

SPECIFICATION forming part of Letters Patent No. 644,050, dated February27, 1900.

Application filed December 9, 1899.

To all whom it may concern:

Be it known that I, HERMANN BEOKMANN, a subject of the German Emperor,residing at Witten-on-the-Ruhr, Germany, have invented a certain new anduseful Improvement in the Manufacture of Lead Peroxid and itsApplication to Electrical Storage Batteries, (Case No. 1,) of which thefollowing is a full, clear, concise, and exact description.

This invention relates to the production of lead peroxid andthe'application thereof as a durable peroxid coating for theelectrodeplates of storage batteries of the Plant kind.

While the use of sulfite compounds have heretofore been consideredunsuitable for the production of peroxid plates of the Plant kind, Ihave, on the other hand, discovered by means of experiments that, forexample, the formation of lead peroxid from metallic lead by means ofthe electric current can be effected in the presence of free sulfurousacid in a much shorter time and in an essentially more favorable mannerthan is the case with the method of the Plant formation heretoforeemployed. The process may be carried out in such a way that, forexample, metallic lead in suitable form is introduced as a'positiveelectrode in a solution of free sulfurous acid and is then subjected tothe action of an'electric current.

The sulfurous-acid solution can be prepared by introducing sulfur dioxidinto water or by dissolving a salt that, in conjunction with an acid,will generate sulfur dioxid in water, to which an acid is added. In thelatter case sodium hyposulfite is preferably employed. By the additionof a definite small quantity of sulfuric acid'this is at once partiallydecomposed and sulfurous anhydrid is set free. If the electric currentbe then introduced, a good strong peroxid coating is obtained on thepositive electrode-plate.

If the introduction of the current be delayed for some time until thesulfurous acid has by oxidation been gradually converted into sulfuricacid or has escaped and the process be accelerated by stirring orblowing in air, no appreciable quantity of peroxid coating will beobtained, which proves that in this case the sulfurous acid alone causesthe formation of the peroxid.

The advantage of the formation of the plates by means of theabove-described invention consists, mainly, in that no subgerial No.739,778. (No specimens.)

stances that are detrimental to the duration of the electrodes-such aschlorin, saltpeter, &c.are employed. It is therefore not necessary tosubject the plates after termination of the formation to the dischargingaction or otherwise to remove any residues of the forming liquid. Theplates are therefore taken directly as they come from the formingsolution and are fitted into the storage vessels. Also the lengthenedpreliminary charging of the plates in the storage vessel is renderedunneccessary with the improved process, such a charging havingheretofore been frequently necessary with Plant electrode-plates forremoving any salt residues from the same.

The formation of peroxid is efiected under the conditions above statedin a considerably shorter space of time than according to theexistingprocesses. Already afterthirtyhours the plate is covered with aperoxid coating of such thickness as to be capable of being used as apole-plate in a storage battery.

Having now particularly described and ascertained the nature of myinvention and the manner in which the same is to be performed, I declarethat what I claim is- 1. A process for producinglead peroxidparticularly as a coating for the electrodes of storage batteries whichconsists in introducing metallic lead into a solution of free sulfurousacid as a positive electrode and subjecting it to the action of anelectric current.

2. A process for producing lead peroxid particularly as a coating forthe electrodes of storage batteries which consists in introducingmetallic lead into a solution of a salt that in conjunction with an acidwill generate sulfur dioxid adding a suitable acid and sulo- HERMANNBEOKMANN.

TVitnesses:

OTTO KONIG, JOHN A. RITTERSHAUS.

